Creating New Maps

To create new maps, you can use one of two possible procedures: the first method uses an existing text file as input; the second uses standard input.

Creating Maps From Text Files

Assume that a text file /var/yp/mymap.asc was created with an editor or a shell script on the master. You want to create an NIS map from this file and locate it in the homedomain subdirectory. To do this, type the following on the master server:

# cd /var/yp
# makedbm mymap.asc homedomain/mymap

The mymap map now exists on the master server in the directory homedomain. To distribute the new map to slave servers run ypxfr.

Adding Entries to a File-Based Map

Adding entries to mymap is simple. First, you must modify the text file /var/yp/mymap.asc. (If you modify the actual dbm files without modifying the corresponding text file, the modifications are lost.) Then run makedbm as shown above.

Creating Maps From Standard Input

When no original text file exists, create the NIS map from the keyboard by typing input to makedbm, as shown below (end with Control-D):

Modifying Maps Made From Standard Input

If you later need to modify the map, you can use makedbm to disassemble the map and create a temporary text intermediate file. To disassemble the map and create a temporary file, type the following:

% cd /var/yp
% makedbm -u homedomain/mymap > mymap.temp

The resulting temporary file mymap.temp has one entry per line. You can edit this file as needed, using any text editor.

To update the map, give the name of the modified temporary file to makedbm by typing the following:

% makedbm mymap.temp homedomain/mymap
% rm mymap.temp

Then propagate the map to the slave servers, by becoming root and typing:

# yppush mymap

The preceding paragraphs explained how to use makedbm to create maps; however, almost everything you actually have to do can be done by ypinit and Makefile unless you add nondefault maps to the database or change the set of NIS servers after the system is already up and running.

Whether you use the Makefile in /var/yp or some other procedure the goal is the same: a new pair of well-formed dbm files must end up in the maps directory on the master server.